getopt and Solaris 10

Apparently Solaris 10 includes a getopt.h and appears to be GNU getopt
by all the tests in getopt.m4.  Unfortunately, it doesn't support "+" as
the first character of the option string.  The original report is here:
<https://ccvs.cvshome.org/issues/show_bug.cgi?id=248>.

I'm assuming that GNULIB is still avoiding AC_TRY_RUN since it doesn't
work when cross-compiling?  I've asked Matthias (the bug reporter, CC'd)
if he could find some difference between Solaris 10's getopt and GNU
getopt that could be detected at compile time.  The alternative would be
always using the GNULIB getopt when installed.

Regards,

Derek